We used the variance analysis method to analyze the effects of the proportion of the actual operated load, the pulseon degree of guide baffles, the temperature of cold water of the outlet, and outdoor relative humidity on the coefficient of performance (COP) of centrifugal refrigerating units. When the confidence level is set as 95% and 99%, respectively, the results of singlefactor variance analysis of the above four parameters show that the test statisticF of the pulseon degree of guide baffles is higher than its critical value F0.01 (r-1,n-r), which establishes that its influence on the COP is quite remarkable. The test statistic F of the proportion of the actual operated load and the outlet temperature of cold water are higher than their own critical value F0.05 (r-1,n-r), which shows that their influence on the COP is remarkable. The test statistic F of outdoor relative humidity is lower than its critical value F0.05 (r-1,n-r), which demonstrates that its influence on the COP is unremarkable. The results of the twofactor variance analysis of the cold water outlet temperature and outdoor relative humidity show that the test statistic F of their interaction is higher than its critical value F0.01 (r-1,n-r), which indicates that influence of their interaction on the COP is very remarkable. The actual COP value of centrifugal refrigerating units can increase by 6.885% in average on the condition of the invariable refrigerating capacity after adjustment according to the analytical results.